Method for producing chain link and a corresponding chain link of a cable drag chain

ABSTRACT

The invention relates to a method for producing a plastic chain link, which has interspaced plates ( 10, 11 ) as well as lower and upper cross-connecting elements ( 15 ) that connect said plates, whereby at least one cross-connecting element is connected to one of the plates ( 10 ) in an articulated manner. According to the invention, at least one of the plates is firstly produced followed by the production of at least one of the cross-connecting elements while simultaneously forming a joint connection between one of the plates and one of the cross connecting elements.

[0001] The object of the invention concerns a method for production of a chain link, as well as a chain link for the power transfer chain.

[0002] A chain link for a power transfer chain is known from DE 43 13 075 A1, which has two opposite link plates at a spacing from each other. The link plates are connected by a crosspiece. Connection of the crosspiece with the plates occurs by releasable hinges. The crosspiece can be locked to the plate. For this purpose, the crosspiece according to DE 43 13 075 A1 has means of locking that cooperate with corresponding means of locking of the link plates. It is specifically proposed by DE 43 13 075 A1 that the crosspiece have shoulders on both sides that are connected to pivots with a round cross section. The link plates have slits to accommodate the shoulders. In the region of the slits, the side plates have recesses for locking the combination and guiding of the pivots. By this configuration of the hinges, pivoting of the crosspiece by 180° is made possible, so that the crosspiece can be brought into any position.

[0003] Another variant of a chain link for a power transfer chain is known from DE 33 18 565 C2. The chain link has two opposite link plates at a spacing from each other, which are connected via a closing shackle. The closing shackle is connected to a link plate with a releasable hinge and can be locked to the other link plate with an elastic hook. DE 33 18 565 C2 proposes, for configuration of the hinge, that it consist of an exposed link axis formed in the free edge of a side plate, with a round cross section flattened perpendicular to the link plate and rounded narrow sides, and of partially circular recesses provided with undercuts, formed in the end of the closing shackle. Because of this configuration of the closing shackle, a possibility is created that, after the closing shackle is mounted on the axis and pivoted in the direction toward the opposite link plate, the closing shackle is tightened to the link axis by force-fitting and shape-mating. This type of closing shackle can be pivoted on one side.

[0004] A plastic chain link for a power transfer chain is known from WO 95/28273. The chain link is formed by two spaced plates. These are connected by an upper and lower crosspiece. One of the crosspieces is articulated with a plate. This crosspiece is connected to the plate unreleasably. To form the link connection, the individual parts of the chain link are initially prepared. The crosspiece has a link head, from which a first tab and a second fork tab extend in fork-like fashion. The fork-like tabs run essentially parallel to each other on their insides. The link head with the molded-on tabs has a groove that corresponds to the peripheral cross section of a pin. To form the link connection, the link head is joined to the tabs and pins. By means of an attachment tool, adapted in shape to the connection being formed, this is brought to the ends of the tabs. Under the influence of a force on the attachment tool and optionally under the influence of heat, the tabs are deformed so that their ends are moved toward each other. In this way, enclosure of the pin by the tabs is achieved. The tabs are then deformed relative to each other, so that they come in contact and finally are joined to each other. The pin is fully enclosed by the link head by joining.

[0005] With this as a point of departure, the underlying objective of the present invention is to provide a method that is easier to perform, in which the number of parts to be handled is supposed to be reduced. Another objective of the invention is to provide a chain link that has at least one crosspiece connected unreleasably to a plate, in which the chain link is easy to manufacture.

[0006] These objectives are achieved by the method according to the invention according to claim 1 and by the chain link according to the invention according to claim 14. Other advantageous designs and embodiments of the method or the chain link are objects of the corresponding dependent claims.

[0007] The method according to the invention for production of a plastic chain link that has spaced plates and lower and upper crosspieces connecting them is characterized by the fact that at least one crosspiece is articulated with one of the plates, during which at least one of the plates is formed, and then at least one of the crosspieces is formed during simultaneous formation of a link connection between one the plates and one of the crosspieces.

[0008] Because of this procedure according to the invention, departing from the product production known from WO 95/28273, a situation is achieved in which a special configuration of the crosspiece with tabs can be dispensed with. In addition, no additional steps necessary to deform the tabs and form the link connection are prescribed. The method according to the invention can be executed with simple tools.

[0009] According to an advantageous embodiment of the method, it is proposed that a plate initially be formed with a link axis, which is enclosed by it during formation of the crosspiece by a peripheral angle greater than 80°. Plates having a link axis are known per se. The essential design of the plates can therefore be used to implement the procedure according to the invention. No fundamental change in design of the plate is therefore required in order to execute the method according to the invention. The link axis is preferably formed in a recess.

[0010] According to another advantageous embodiment of the method, it is proposed that one plate initially be formed with at least one link mount extending in the longitudinal direction of the plate. This link mount is preferably partially circular in cross section, so that at least one link pivot can be formed in the link mount during formation of the crosspiece. The materials from which the plates or crosspieces are preferably made are preferably chosen so that they do not join to each other. This expedient ensures that a pivoting movement of the crosspiece relative to the plate is made possible.

[0011] According to another advantageous embodiment of the method, it is proposed that the plate have a partially circular link mount in cross section, whose peripheral angle is greater than 180° and less than 360°. In particular, it is proposed that the peripheral angle be about 270°.

[0012] According to another advantageous embodiment of the method, it is suggested that the plate have opposite link mounts, in which one link pivot each is formed during formation of the crosspiece.

[0013] To reduce the number of parts to be handled for a chain link, according to another advantageous variant of the method, it is proposed that the plates and one crosspiece be formed as a one-piece, U-shaped part.

[0014] To reduce production costs and design expense of a chain link, it is proposed that the plates and/or crosspieces be designed to be the same.

[0015] Production of a chain link preferably occurs by forming at least one crosspiece according to the two-component injection molding method, with simultaneous formation of the link connection between one of the plates and one of the crosspieces. The two-component injection molding method can therefore be conducted in a single machine.

[0016] According to another advantageous variant of the method, it is proposed that the plates and/or at least one crosspiece be formed at least partially from different plastics. The plates and optionally one crosspiece preferably consist of a plastic chosen from the group of polyamides. To increase the stability of the plates and optionally of the U-shaped part, it is proposed that they be produced from polyamides provided with fiberglass reinforcement.

[0017] The plates and optionally the crosspiece can preferably be made from the plastic chosen from the group of polyacetals. The plastic, in particular, is POM here.

[0018] According to another inventive idea, a plastic chain link is proposed for a power transfer chain that has space plates and lower and upper crosspieces connecting them, in which at least one crosspiece is articulated with one of the plates, one section of the crosspiece seamlessly enclosing a link axis formed on the plate. By this expedient, the crosspiece is unreleasably joined to the plate. Owing to the fact that the plate and the crosspiece are seamlessly joined to each other, higher forces can act on the crosspiece without loosening of the crosspiece from the plate. The chain link according to the invention is particularly suited for the formation of a power transfer chain with very small chain links.

[0019] According to another advantageous design of a plastic chain link, it is proposed that at least one section of a crosspiece be formed with one of the plates during simultaneous formation of a link connection.

[0020] The section preferably encloses a link axis of the plate over a peripheral angle greater than 180°.

[0021] According to another advantageous variant of the chain link, it is proposed that one plate have at least one link mount extending in the longitudinal direction of the plate, into which a link pivot extends, which is formed during formation of the crosspiece.

[0022] In particular, it is proposed that the chain link be formed of the plate having two opposite link mounts. A link pivot extends into each of the link mounts, the link pivots being formed during formation of the crosspiece.

[0023] The chain link is preferably formed by a crosspiece that is articulated with one of the plates. This plate is connected to the second plate via another crosspiece, in which the plates and the crosspiece form a U-shaped component.

[0024] According to another advantageous design of the chain link, it is proposed that the at least one crosspiece be formed according to the two-component injection molding method, with simultaneous formation of the link connection between one of the plates and one of the crosspieces.

[0025] According to another advantageous embodiment of the chain link, it is proposed that the plates and the at least one crosspiece be formed at least partially from different plastics. In particular, it is proposed that the plates and optionally one crosspiece be formed from a plastic chosen from the group of polyamides.

[0026] According to another advantageous design of the chain link, the plates and optionally one crosspiece are formed from a plastic chosen from the group of polyacetals.

[0027] Additional details and advantages of the method and the chain link according to the invention are explained with reference to the practical examples depicted in the drawing.

IN THE DRAWING

[0028]FIG. 1 schematically depicts a first practical example of a chain link in a front view,

[0029]FIG. 2 depicts a cross section along line A-A of FIG. 1,

[0030]FIG. 3 depicts a U-shaped chain link part,

[0031]FIG. 4 depicts another practical example of a chain link in cross section along line B-B according to FIG. 5,

[0032]FIG. 5 shows a front view of the chain link,

[0033]FIG. 6 shows a perspective view of a U-shaped chain link part of the chain link according to FIG. 5,

[0034]FIG. 7 shows a chain link according to FIG. 5 in a perspective view,

[0035]FIG. 8 shows another practical example in perspective view from the top,

[0036]FIG. 9 shows the chain link according to FIG. 8 in a perspective view from the bottom,

[0037]FIG. 10 shows a variant of a plate of a chain link,

[0038]FIG. 11 shows a cross section along line A-A of FIG. 10, and

[0039]FIG. 12 shows a cross section of the plate according to FIG. 10, with a crosspiece.

[0040] FIGS. 1 to 3 show a first practical example of a chain link according to the invention. FIG. 3 schematically depicts a U-shaped chain link part in a perspective view.

[0041] The chain link is made from plastic. It is provided for a power transfer chain that can consist of a number of such chain links. The chain link has two spaced plates 10, 11. In the depicted practical example, the plates 10, 11 are joined by a lower rigid crosspiece 18. Each plate 10, 11 has a hole 12 on one end region. A pivot 13 is provided in the opposite end region of plates. The holes 12 or pivots 13 of the chain plates 10, 11 are designed so that a pivot 13 can be inserted into the hole 12 of a link plate of an adjacent chain link, so that several link plates can be joined together, forming a strand. This design of a power transfer chain in known per se.

[0042] Starting from edge 17 of plate 10 and across the longitudinal extent of plate 10, a recess 14 is provided. A link axis 16 formed within recess 14 is present that forms a component of plate 10. The link axis 16 has a circular cross section, as is apparent from FIG. 2.

[0043] A crosspiece 15 is articulated with plate 1. FIG. 2 shows that a section of the crosspiece 15 surrounds the link axis 16 seamlessly.

[0044] The crosspiece 15 has a hook 19 on its free end. The hook 19 has a hook nose 23, as well as a pin mount 24.

[0045] Starting from the longitudinal edge 17 of plate 11 and across the longitudinal extent of plate 11, a hook mount 20 is provided. The hook mount 20, as is particularly apparent from FIG. 3, has a pin 21 running in the longitudinal direction of the plate 11. A protrusion 22 is provided in the outer wall of plate 11.

[0046] The crosspiece 15 is pivotable around the link axis. In the closed state of the chain link, pin 21 engages in the pin mount 24 of hook 19. Beneath pin 21, protrusion 22 is formed, which cooperates with hook nose 23, so that the crosspiece 15 can be joined releasably to plate 11. Pin 21, which engages in the closed state in pin mount 24, prevents inadvertent opening of the crosspiece 16, when plates 10, 11 are moved relative to each other.

[0047] The chain link depicted in FIGS. 1 and 2 can be produced as follows:

[0048] The plates of the chain link are initially formed. Here, at least plate 10 has a link axis 16. The crosspiece 15 is then formed during simultaneous formation of a link connection between plate 10 and crosspiece 15.

[0049] The chain link depicted in FIGS. 1 to 3 has a U-shaped chain link part formed from plates 10, 11 and crosspiece 18. This is not absolutely necessary. The crosspiece 18 can also be releasably joined to plates 10,11.

[0050] There is also the possibility of providing two crosspieces articulated with the plates on one of the two plates. These crosspieces can be connected to the opposite plate. There is also the possibility of forming the plate 11 with a crosspiece 15 that is articulated with plate 11.

[0051] FIGS. 4 to 7 show another practical example of the chain link according to the invention.

[0052] The chain link depicted in FIGS. 4 to 7 has a U-shaped chain link part. The chain link has two spaced plates 30, 31. The plates 30, 31 are joined by a lower crosspiece 38.

[0053] Each plate 30, 31 has a hole 32 in an end region of the plate. A pivot 33 is formed in the opposite end region. The hole 32 and pivot 33 of a chain link form the possibility of articulation with additional chain links, so that these form a power transfer chain.

[0054] The chain link has an upper crosspiece 35 articulated with plate 30. For articulation, the plate 30 has link mounts 34. These link mounts 34 are adjacent to edge 37 in the depicted practical example and are formed on the inside surface of plate 30. Two link mounts 34 are provided, designed at a spacing to each other. FIG. 4 shows that in each link mount 34, a link pivot 36 extends. The link pivots 36 are formed on crosspiece 35. The crosspiece 35 is articulated with plate 30 by the link mount 34 and link pivot 36. FIGS. 4, 5 and 7 show the chain link in the opened state. For closure of the chain link, the crosspiece 35 is pivoted in the direction of the opposite plate 31. The pin 41, formed in a hook mount 40 of plate 31, enters the pin mount 44 of the hook 39, provided on the free end of crosspiece 35. During further movement of crosspiece 35 in the direction of plate 31, the hook nose 43 locks behind the protrusion 42 formed on plate 31, so that the crosspiece 35 is locked to plate 31.

[0055] Another practical example of the chain link according to the invention is shown in FIGS. 8 and 9. The essential design of the chain link depicted in FIGS. 8 and 9 corresponds to the chain link shown in FIGS. 4 to 7.

[0056] The chain link depicted in FIGS. 8 and 9 has two spaced plates 50, 51. The plates 50, 51 are joined by a crosspiece 56. Each plate 50, 51 has a hole 52 and a pivot 53. The pivots 53 of the plates of an adjacent chain link enter the holes 52 of plates 50, 51. A number of such chain links form a power transfer chain.

[0057] The chain link shown in FIGS. 8 and 9 has a plate 51 that has a recess 54 from longitudinal edge 57 and in the longitudinal direction, as well as across the longitudinal direction of the plate. Opposite link mounts are formed in the side walls of recess 54. Link pivots extend into the link mounts, through which the crosspiece 55 is connected to pivot with plate 51. Formation of the link pivots, which is not shown in FIGS. 8 and 9, occurs during formation of the crosspiece 55.

[0058]FIG. 10 shows a plate 1 of the chain link, in which the plate 70 has a hole 72 and a pivot 71. Hole 72 and pivot 71 are formed on the opposite end regions of plate 70. A link mount 74 is formed in the edge 73 and in the longitudinal direction of the plate, as is particularly apparent from FIG. 11.

[0059] The link mount 74 has a partially circular cross section. FIG. 12 shows that a link pivot 76 is situated in the link mount 74, which had been formed during production of the crosspiece 75. The crosspiece 75 is pivotable by an angle of about 90°. A hook 77 is formed on the end of crosspiece 75 opposite link pivot 76, which can be locked to an opposite link plate. Locking is preferably designed so that it is releasable. To improve rigidity of the crosspiece 75, it can have a rib.

List of Reference Numbers

[0060]10 Plate

[0061]11 Plate

[0062]12 Hole

[0063]13 Pivot

[0064]14 Recess

[0065]15 Crosspiece

[0066]16 Link axis

[0067]17 Edge

[0068]18 Crosspiece

[0069]19 Hook

[0070]20 Hook mount

[0071]21 Pin

[0072]22 Protrusion

[0073]23 Hook nose

[0074]24 Pin mount

[0075]30 Plate

[0076]31 Plate

[0077]32 Hole

[0078]33 Pivot

[0079]34 Link mount

[0080]35 Crosspiece

[0081]36 Link pivot

[0082]37 Edge

[0083]38 Crosspiece

[0084]39 Hook

[0085]40 Hook mount

[0086]41 Pin

[0087]42 Protrusion

[0088]43 Hook nose

[0089]44 Pin mount

[0090]50 Plate

[0091]51 Plate

[0092]52 Hole

[0093]53 Pivot

[0094]54 Recess

[0095]55 Crosspiece

[0096]56 Crosspiece

[0097]57 Edge

[0098]58 Hook

[0099]59 Pin

[0100]60 Hook mount

[0101]70 Plate

[0102]71 Pivot

[0103]72 Hole

[0104]73 Edge

[0105]74 Link mount

[0106]75 Crosspiece

[0107]76 Link pivot

[0108]77 Hook

[0109]78 Rib 

1. Method for the production of a plastic chain link, having spaced plates (10, 11, 30, 31, 50, 51, 70) and lower and upper crosspieces (15, 18, 35 38, 55, 56, 75) connecting them, in which at least one crosspiece (15, 35, 55, 75) is articulated to a plate (10, 30, 50, 70), in which at least one of the plates (10, 30, 50, 70) and then at least one of the crosspieces (15, 35, 55, 75) are formed during simultaneous formation of a link connection between one of the plates (10, 30, 50, 70) and one of the crosspieces (15, 35, 55, 75).
 2. Method according to claim 1, in which initially one plate (10) is formed with a link axis (16), which, during formation of the crosspiece (15), is enclosed by it by a peripheral angle greater than 180°.
 3. Method according to claim 2, in which the link axis (16) is formed in a recess (16).
 4. Method according to claim 1, in which initially a plate (30, 50, 70) is formed with at least one link mount (34, 74) extending in the longitudinal direction of the plate (30, 50, 70), in which at least one link pivot (36, 76) is formed during formation of the crosspiece (35, 55, 75).
 5. Method according to claim 4, in which opposite link mounts (34) are formed in plate (30, 50), in which a link pivot (36) is formed during formation of the crosspiece (35, 55).
 6. Method according to claim 4, in which a link mount (74) with a partially circular cross section is formed in the plate (70), whose peripheral angle is greater than 180° and smaller than 360°.
 7. Method according to claim 6, in which a link mount (74) with a partially circular cross section is formed in the plate (70), whose peripheral angle is about 270°.
 8. Method according to one of the claims 1 to 7, in which the plates (10, 11, 30, 31, 50, 51) and a crosspiece (18, 38, 56) form a one-piece U-shaped part.
 9. Method according to one of the claims 1 to 7, in which the plates (10, 11, 30, 31, 50, 51, 70) and/or crosspieces (15, 18, 35, 38, 55, 56, 75) are designed identical.
 10. Method according to one of the claims 1 to 9, in which the at least one crosspiece (15, 35, 55, 75) is formed according to the two-component injection molding method, with simultaneous formation of the link connection between one of the plates (10, 30, 50, 70) and one of the crosspieces (15, 35, 55, 75).
 11. Method according to one of the claims 1 to 10, in which the plates (10, 11, 30, 31, 50, 51, 70) and/or at least one crosspiece (15, 18, 35, 38, 55, 56, 75) are formed at least partially from different plastics.
 12. Method according to claim 11, in which the plates (10, 11, 30, 31, 50, 51, 70) and optionally one crosspiece (15, 18, 35, 38, 55, 56, 75) are formed from a plastic chosen from the group of polyamides.
 13. Method according to claim 11 or 12, in which the plates (10, 11, 30, 31, 50, 51, 70) and optionally one crosspiece (15, 18, 35, 38, 55, 56, 75) are formed from a plastic chosen from the group of polyacetals.
 14. Plastic chain link for a power transfer chain, having spaced plates (10, 11) and lower and upper crosspieces (15, 18) connecting them, in which at least one crosspiece (15) is articulated to one of the plates (10), characterized by the fact that a section of crosspiece (15) seamlessly encloses a link axis (16) formed on plate (10).
 15. Plastic chain link for a power transfer chain, having spaced plates (10, 11, 30, 31, 50, 51, 70) and lower and upper crosspieces (15, 18, 35, 38, 55, 56, 75) connecting them, in which at least one crosspiece (15, 35, 55, 75) is articulated to one of the plates (10, 30, 50, 70), especially according to claim 14, characterized by the fact that at least one section of a crosspiece (15, 35, 55, 75) is formed during simultaneous formation of a link connection with one of the plates (10, 30, 50, 70).
 16. Chain link according to claim 15, characterized by the fact that the section encloses a link axis (16) of plate (10) over a peripheral angle greater than 180°.
 17. Chain link according to claim 15, characterized by the fact that a plate (30, 50, 70) has at least one link mount (34, 74) extending in the longitudinal direction of the plate (30, 50, 70), into which a link pivot (36, 76) extends, which is formed during formation of crosspiece (35, 55, 75).
 18. Chain link according to claim 17, characterized by the fact that the plate (30, 50) has two opposite link mounts (34), into which a link pivot (36) extends at least partially, in which the link pivots (36) are formed during formation of the crosspiece (35, 55).
 19. Chain link according to one of the claims 14 to 18, characterized by the fact that the plates (10, 11, 30, 31, 50, 51, 70) and a crosspiece (15, 18, 35, 38, 55, 56, 75) form a one-piece, U-shaped part.
 20. Chain link according to one of the claims 14 to 19, characterized by the fact that the at least one crosspiece (15, 35, 55, 75) is formed according to the two-component injection molding method, with simultaneous formation of the link connection between one of the plates (10, 30, 50, 70) and one of the crosspieces (15, 35, 55, 75).
 21. Chain link according to one of the claims 14 to 20, characterized by the fact that the plates (10, 11, 30, 31, 50, 51, 70) and the at least one crosspiece (15, 18, 35, 38, 55, 56, 75) are formed at least partially from different plastics.
 22. Chain link according to claim 21, characterized by the fact that the plates (10, 11, 30, 31, 50, 51, 70) and optionally one crosspiece (15, 18, 35, 38, 55, 56, 75) are formed from a plastic chosen from the group of polyamides.
 23. Chain link according to claim 22 or 23, characterized by the fact that the plates (10, 11, 30, 31, 50, 51, 70) and optionally one crosspiece (15, 18, 35, 38, 55, 56, 75) are formed from a plastic chosen from the group of polyacetals. 